P1171: REFLECT: PROSPECTIVE NON-INTERVENTIONAL STUDY ON THE EFFECTIVENESS AND SAFETY OF SANDOZ RITUXIMAB (SDZ-RTX) WITH CHOP FOR PATIENTS WITH PREVIOUSLY UNTREATED CD20-POSITIVE DIFFUSE LARGE B-CELL LYMPHOMA
Authors: M. Welslau, B. Kubuschok, J. Topaly, B. Otremba, T. Wolff, G. Bryn
Journal: HemaSphere (2022)

Background: Sandoz biosimilar rituximab (SDZ-RTX) was approved in the EU for all the indications of reference rituximab. REFLECT is a real-world, multicenter, open-label, single-arm, non-interventional trial, and is the first prospective, post-approval study of SDZ-RTX in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) as a curative therapy for patients with CD20-positive diffuse large B-cell lymphoma (DLBCL). Aims: The aim of the REFLECT study was to evaluate the 2-year effectiveness and safety of SDZ-RTX as first-line treatment for DLBCL. Methods: Treatment-naïve, CD20-positive adult patients (aged ≥18 years) with DLBCL eligible for therapy with R-CHOP were treated with SDZ-RTX-CHOP every 2 or 3 weeks for 6–8 cycles according to the product label, as per routine clinical practice. Data was collected at enrollment, at every patient contact during the 12-month treatment period, and at one time point ≥30 days after the last dose of R-CHOP. Complete response was defined as the best result, as assessed by the treating physician using the Response Evaluation Criteria in Lymphoma 2017 (RECIL criteria). Kaplan–Meier estimates of progression free survival (PFS) were assessed at 24 months. No imputation for missing data was used; endpoints were summarized descriptively. All patients provided written informed consent prior to study entry. The cut-off for data collection was March 31, 2021. Results: A total of 169 patients (52.1% female, mean [standard deviation] age 67.3 [13.4] years) with DLBCL were included in the full analysis set. At baseline, 19.5% and 24.3% of patients had Ann Arbor disease stage III or IV, respectively, and most patients (80.5%) had Eastern Cooperative Oncology Group performance score of 0 or 1. In terms of International Prognostic Index, 92 (54.5%) patients had a score of ≥2 at baseline. A total of 100 (59.2%) patients completed the 24-month observation period. In total, 110 (65.1%; 95% confidence interval [CI] 57.4–72.3) patients achieved complete response as the best response and 50 (29.6%; 95% CI 22.8–37.1) patients achieved partial response. The overall response rate was 94.7% (95% CI 90.1–97.5). One-year PFS was 84.9% (95% CI 78.2–89.6), while 2-year PFS was 78.5% (95% CI 70.9–84.4) (Figure 1); median PFS was not reached within the observational period. A total of 143 (84.6%) patients experienced at least one adverse event (AE), 53 (31.4%) of which were suspected to be related to the study drug. The most common AEs were anemia (24.3%), fatigue (20.7%), polyneuropathy (17.2%), and nausea (12.4%). Serious AEs were reported in 63 (37.3%) patients, with those suspected to be related to the study drug reported in 11 (6.5%) patients. AEs requiring dose interruption and/or dose change were reported in 24 (14.2%) patients. There were 8 (4.7%) deaths recorded during the study, of which 3 (1.8%) occurred during the on-treatment period. Image:Summary/Conclusion: This real-world, post-approval study reconfirms that first-line treatment of CD20-positive DLBCL with R-CHOP using SDZ-RTX is effective over a 24-month observation period, with no unexpected safety signals. These data may help to broaden patient access to rituximab-based chemotherapy and support the sustainability of cancer care.